Minimum-till (MT) and no-till (NT) systems were evaluated for converting seeded grassland back to cropland. Nitrogen fertilization needs to optimize grain yields following grass and to optimize hay yields from the grassland were also evaluated. Tillage treatments - conventional till (CT), MT, and NT- were established on a Weld silt loam soil that had been seeded to grass about 30 yr following more than 30 yr of crop-fallow. Nitrogen treatments were 0, 45, and 30 kg N/hn (0, 40, and 80 lb N/a) applied to each crop in a winter wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow rotation or annually to grass plots. Residue cover at wheat planting averaged 18, 44, and 73% for CT; MT; and NT; respectively Soil water recharge was minimal between grass kill and wheat planting; however soil NO3-N increased 115, 63, and 54 kg N/ha (103, 62, and 48 lb N/ac) for CT, MT, and NT respectively. Wheat grain yields were greater with CT 2,685 kg/ha (40 bu/ac) and MT 2,558 kg/ha (38 bu/ac) than with NT 2,052 kg/ha (30.5 bu/ac). Lower wheat yields with NT resulted from lack of grass control Wheat yield responses to N varied with year and were dependent on available water supplies. Corn grain yields were low, [1,233, 2,063, and 1,564 kg/ha (19.7, 32.9, and 24.9 bu/ac) for CT; MT, and NT; respectively] due to limited growing season water. Average wheat 6,298 kg/ha (5,623 lb/ac) and corn 5,040 kg/ha (4,500 lb/ac) phytomass production exceeded that of the fertilized grass [1,529 kg/ha with 90 kg N/ha (1,365 lb/ac with 80 lb N/ac)]. Producers converting CRP grass to crop production can use MT and NT practices to maintain soil erosion control.
